1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/arch/arm/mach-footbridge/common.c
4  *
5  *  Copyright (C) 1998-2000 Russell King, Dave Gilbert.
6  */
7 #include <linux/module.h>
8 #include <linux/types.h>
9 #include <linux/mm.h>
10 #include <linux/ioport.h>
11 #include <linux/list.h>
12 #include <linux/init.h>
13 #include <linux/io.h>
14 #include <linux/spinlock.h>
15 #include <video/vga.h>
16 
17 #include <asm/pgtable.h>
18 #include <asm/page.h>
19 #include <asm/irq.h>
20 #include <asm/mach-types.h>
21 #include <asm/setup.h>
22 #include <asm/system_misc.h>
23 #include <asm/hardware/dec21285.h>
24 
25 #include <asm/mach/irq.h>
26 #include <asm/mach/map.h>
27 #include <asm/mach/pci.h>
28 
29 #include "common.h"
30 
31 unsigned int mem_fclk_21285 = 50000000;
32 
33 EXPORT_SYMBOL(mem_fclk_21285);
34 
35 static int __init early_fclk(char *arg)
36 {
37 	mem_fclk_21285 = simple_strtoul(arg, NULL, 0);
38 	return 0;
39 }
40 
41 early_param("mem_fclk_21285", early_fclk);
42 
43 static int __init parse_tag_memclk(const struct tag *tag)
44 {
45 	mem_fclk_21285 = tag->u.memclk.fmemclk;
46 	return 0;
47 }
48 
49 __tagtable(ATAG_MEMCLK, parse_tag_memclk);
50 
51 /*
52  * Footbridge IRQ translation table
53  *  Converts from our IRQ numbers into FootBridge masks
54  */
55 static const int fb_irq_mask[] = {
56 	IRQ_MASK_UART_RX,	/*  0 */
57 	IRQ_MASK_UART_TX,	/*  1 */
58 	IRQ_MASK_TIMER1,	/*  2 */
59 	IRQ_MASK_TIMER2,	/*  3 */
60 	IRQ_MASK_TIMER3,	/*  4 */
61 	IRQ_MASK_IN0,		/*  5 */
62 	IRQ_MASK_IN1,		/*  6 */
63 	IRQ_MASK_IN2,		/*  7 */
64 	IRQ_MASK_IN3,		/*  8 */
65 	IRQ_MASK_DOORBELLHOST,	/*  9 */
66 	IRQ_MASK_DMA1,		/* 10 */
67 	IRQ_MASK_DMA2,		/* 11 */
68 	IRQ_MASK_PCI,		/* 12 */
69 	IRQ_MASK_SDRAMPARITY,	/* 13 */
70 	IRQ_MASK_I2OINPOST,	/* 14 */
71 	IRQ_MASK_PCI_ABORT,	/* 15 */
72 	IRQ_MASK_PCI_SERR,	/* 16 */
73 	IRQ_MASK_DISCARD_TIMER,	/* 17 */
74 	IRQ_MASK_PCI_DPERR,	/* 18 */
75 	IRQ_MASK_PCI_PERR,	/* 19 */
76 };
77 
78 static void fb_mask_irq(struct irq_data *d)
79 {
80 	*CSR_IRQ_DISABLE = fb_irq_mask[_DC21285_INR(d->irq)];
81 }
82 
83 static void fb_unmask_irq(struct irq_data *d)
84 {
85 	*CSR_IRQ_ENABLE = fb_irq_mask[_DC21285_INR(d->irq)];
86 }
87 
88 static struct irq_chip fb_chip = {
89 	.irq_ack	= fb_mask_irq,
90 	.irq_mask	= fb_mask_irq,
91 	.irq_unmask	= fb_unmask_irq,
92 };
93 
94 static void __init __fb_init_irq(void)
95 {
96 	unsigned int irq;
97 
98 	/*
99 	 * setup DC21285 IRQs
100 	 */
101 	*CSR_IRQ_DISABLE = -1;
102 	*CSR_FIQ_DISABLE = -1;
103 
104 	for (irq = _DC21285_IRQ(0); irq < _DC21285_IRQ(20); irq++) {
105 		irq_set_chip_and_handler(irq, &fb_chip, handle_level_irq);
106 		irq_clear_status_flags(irq, IRQ_NOREQUEST | IRQ_NOPROBE);
107 	}
108 }
109 
110 void __init footbridge_init_irq(void)
111 {
112 	__fb_init_irq();
113 
114 	if (!footbridge_cfn_mode())
115 		return;
116 
117 	if (machine_is_ebsa285())
118 		/* The following is dependent on which slot
119 		 * you plug the Southbridge card into.  We
120 		 * currently assume that you plug it into
121 		 * the right-hand most slot.
122 		 */
123 		isa_init_irq(IRQ_PCI);
124 
125 	if (machine_is_cats())
126 		isa_init_irq(IRQ_IN2);
127 
128 	if (machine_is_netwinder())
129 		isa_init_irq(IRQ_IN3);
130 }
131 
132 /*
133  * Common mapping for all systems.  Note that the outbound write flush is
134  * commented out since there is a "No Fix" problem with it.  Not mapping
135  * it means that we have extra bullet protection on our feet.
136  */
137 static struct map_desc fb_common_io_desc[] __initdata = {
138 	{
139 		.virtual	= ARMCSR_BASE,
140 		.pfn		= __phys_to_pfn(DC21285_ARMCSR_BASE),
141 		.length		= ARMCSR_SIZE,
142 		.type		= MT_DEVICE,
143 	}
144 };
145 
146 /*
147  * The mapping when the footbridge is in host mode.  We don't map any of
148  * this when we are in add-in mode.
149  */
150 static struct map_desc ebsa285_host_io_desc[] __initdata = {
151 #if defined(CONFIG_ARCH_FOOTBRIDGE) && defined(CONFIG_FOOTBRIDGE_HOST)
152 	{
153 		.virtual	= PCIMEM_BASE,
154 		.pfn		= __phys_to_pfn(DC21285_PCI_MEM),
155 		.length		= PCIMEM_SIZE,
156 		.type		= MT_DEVICE,
157 	}, {
158 		.virtual	= PCICFG0_BASE,
159 		.pfn		= __phys_to_pfn(DC21285_PCI_TYPE_0_CONFIG),
160 		.length		= PCICFG0_SIZE,
161 		.type		= MT_DEVICE,
162 	}, {
163 		.virtual	= PCICFG1_BASE,
164 		.pfn		= __phys_to_pfn(DC21285_PCI_TYPE_1_CONFIG),
165 		.length		= PCICFG1_SIZE,
166 		.type		= MT_DEVICE,
167 	}, {
168 		.virtual	= PCIIACK_BASE,
169 		.pfn		= __phys_to_pfn(DC21285_PCI_IACK),
170 		.length		= PCIIACK_SIZE,
171 		.type		= MT_DEVICE,
172 	},
173 #endif
174 };
175 
176 void __init footbridge_map_io(void)
177 {
178 	/*
179 	 * Set up the common mapping first; we need this to
180 	 * determine whether we're in host mode or not.
181 	 */
182 	iotable_init(fb_common_io_desc, ARRAY_SIZE(fb_common_io_desc));
183 
184 	/*
185 	 * Now, work out what we've got to map in addition on this
186 	 * platform.
187 	 */
188 	if (footbridge_cfn_mode()) {
189 		iotable_init(ebsa285_host_io_desc, ARRAY_SIZE(ebsa285_host_io_desc));
190 		pci_map_io_early(__phys_to_pfn(DC21285_PCI_IO));
191 	}
192 
193 	vga_base = PCIMEM_BASE;
194 }
195 
196 void footbridge_restart(enum reboot_mode mode, const char *cmd)
197 {
198 	if (mode == REBOOT_SOFT) {
199 		/* Jump into the ROM */
200 		soft_restart(0x41000000);
201 	} else {
202 		/*
203 		 * Force the watchdog to do a CPU reset.
204 		 *
205 		 * After making sure that the watchdog is disabled
206 		 * (so we can change the timer registers) we first
207 		 * enable the timer to autoreload itself.  Next, the
208 		 * timer interval is set really short and any
209 		 * current interrupt request is cleared (so we can
210 		 * see an edge transition).  Finally, TIMER4 is
211 		 * enabled as the watchdog.
212 		 */
213 		*CSR_SA110_CNTL &= ~(1 << 13);
214 		*CSR_TIMER4_CNTL = TIMER_CNTL_ENABLE |
215 				   TIMER_CNTL_AUTORELOAD |
216 				   TIMER_CNTL_DIV16;
217 		*CSR_TIMER4_LOAD = 0x2;
218 		*CSR_TIMER4_CLR  = 0;
219 		*CSR_SA110_CNTL |= (1 << 13);
220 	}
221 }
222 
223 #ifdef CONFIG_FOOTBRIDGE_ADDIN
224 
225 static inline unsigned long fb_bus_sdram_offset(void)
226 {
227 	return *CSR_PCISDRAMBASE & 0xfffffff0;
228 }
229 
230 /*
231  * These two functions convert virtual addresses to PCI addresses and PCI
232  * addresses to virtual addresses.  Note that it is only legal to use these
233  * on memory obtained via get_zeroed_page or kmalloc.
234  */
235 unsigned long __virt_to_bus(unsigned long res)
236 {
237 	WARN_ON(res < PAGE_OFFSET || res >= (unsigned long)high_memory);
238 
239 	return res + (fb_bus_sdram_offset() - PAGE_OFFSET);
240 }
241 EXPORT_SYMBOL(__virt_to_bus);
242 
243 unsigned long __bus_to_virt(unsigned long res)
244 {
245 	res = res - (fb_bus_sdram_offset() - PAGE_OFFSET);
246 
247 	WARN_ON(res < PAGE_OFFSET || res >= (unsigned long)high_memory);
248 
249 	return res;
250 }
251 EXPORT_SYMBOL(__bus_to_virt);
252 
253 unsigned long __pfn_to_bus(unsigned long pfn)
254 {
255 	return __pfn_to_phys(pfn) + (fb_bus_sdram_offset() - PHYS_OFFSET);
256 }
257 EXPORT_SYMBOL(__pfn_to_bus);
258 
259 unsigned long __bus_to_pfn(unsigned long bus)
260 {
261 	return __phys_to_pfn(bus - (fb_bus_sdram_offset() - PHYS_OFFSET));
262 }
263 EXPORT_SYMBOL(__bus_to_pfn);
264 
265 #endif
266